Multi-conduit manifolds, systems, and methods for applying reduced pressure to a subcutaneous tissue site

ABSTRACT

The illustrative embodiments described herein are directed to systems, methods, and apparatuses for applying a reduced pressure to a subcutaneous tissue site. In one instance, a manifold for applying reduced pressure to a subcutaneous tissue site includes a plurality of first conduits, each of the plurality of first conduits having a wall with at least one first aperture and at least one second aperture. At least one of the plurality of first conduits is operable to deliver reduced pressure to the subcutaneous tissue site. The plurality of first conduits is coupled in a spaced arrangement that forms an interior space. The manifold further includes a second conduit comprising the interior space and formed by a portion of each wall of the plurality of first conduits. The second conduit is in fluid communication with the plurality of first conduits via the at least one second aperture.

RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 14/489,173, filed Sep. 17, 2014, which is adivisional application of U.S. patent application Ser. No. 12/641,546,filed Dec. 18, 2009, now issued U.S. Pat. No. 8,864,728, which claimsthe benefit, under 35 U.S.C. § 119(e), of the filing of U.S. ProvisionalPatent Application Ser. No. 61/141,728, entitled “Multi-conduitManifolds, Systems, and Methods for Applying Reduced Pressure To aSubcutaneous Tissue Site,” filed Dec. 31, 2008, which is incorporatedherein by reference for all purposes.

BACKGROUND

The present invention relates generally to medical treatment systems,and more particularly, multi-conduit manifolds, systems, and methods forapplying reduced pressure to a subcutaneous tissue site.

Clinical studies and practice have shown that providing a reducedpressure in proximity to a tissue site augments and accelerates thegrowth of new tissue at the tissue site. The applications of thisphenomenon are numerous, but application of reduced pressure has beenparticularly successful in treating wounds. This treatment (frequentlyreferred to in the medical community as “negative pressure woundtherapy,” “reduced pressure therapy,” or “vacuum therapy”) provides anumber of benefits, including faster healing, and increased formulationof granulation tissue. More recently, reduced pressure treatments havebeen utilized at subcutaneous tissue sites.

SUMMARY

To alleviate existing short comings with reduced-pressure treatmentsystems, the illustrative embodiments described herein are directed tosystems, methods, and apparatuses for applying a reduced pressure to asubcutaneous tissue site. According to an illustrative, non-limitingembodiment, a system for applying reduced pressure to a subcutaneoustissue site that includes a reduced-pressure source for supplyingreduced pressure, a fluid source for supplying a fluid, and a manifoldadapted for placement at the subcutaneous tissue site. The manifoldincludes a plurality of first conduits, each of the plurality of firstconduits having a wall formed with at least one first aperture and atleast one second aperture. At least one of the plurality of firstconduits is in fluid communication with the reduced-pressure source andis operable to deliver the reduced pressure to the subcutaneous tissuesite via the at least one first aperture. The manifold further includesa second conduit formed by a portion of each wall of the plurality offirst conduits. The second conduit is in fluid communication with theplurality of first conduits via the at least one second aperture. Thesystem may further include a delivery conduit fluidly coupled to themanifold and reduced-pressure source.

According to another illustrative, non-limiting embodiment, a manifoldfor applying reduced pressure to a subcutaneous tissue site includes aplurality of first conduits, each of the plurality of first conduitshaving a wall with at least one first aperture and at least one secondaperture. At least one of the plurality of first conduits is operable todeliver reduced pressure to the subcutaneous tissue site via the atleast one first aperture. The plurality of first conduits is coupled ina spaced arrangement that forms an interior space. The manifold furtherincludes a second conduit comprising the interior space and formed by aportion of each wall of the plurality of first conduits. The secondconduit is in fluid communication with the plurality of first conduitsvia the at least one second aperture.

According to another illustrative, non-limiting embodiment, a method forapplying reduced pressure to a subcutaneous tissue site includesproviding a manifold, applying the manifold to the subcutaneous tissuesite, and supplying the reduced pressure to the manifold via a deliveryconduit. The manifold includes a plurality of first conduits. Each ofthe plurality of first conduits has a wall with at least one firstaperture and at least one second aperture. At least one of the pluralityof first conduits is operable to deliver reduced pressure to thesubcutaneous tissue site via the at least one first aperture. Theplurality of first conduits are coupled in a spaced arrangement thatforms an interior space. The manifold further includes a second conduitcomprising the interior space and formed by a portion of each wall ofthe plurality of first conduits. The second conduit is in fluidcommunication with the plurality of first conduits via the at least onesecond aperture.

According to another illustrative, non-limiting embodiment, a method ofmanufacturing an apparatus that is applying reduced pressure to asubcutaneous tissue includes providing a plurality of first conduits.Each of the plurality of first conduits has a wall formed with at leastone first aperture and at least one second aperture. At least one of theplurality of first conduits is operable to deliver reduced pressure tothe subcutaneous tissue site via the at least one first aperture. Themethod further includes coupling the plurality of first conduits to oneanother to form a second conduit. The second conduit is formed by aportion of each wall of the plurality of first conduits and is in fluidcommunication with the plurality of first conduits via the at least onesecond aperture.

According to another illustrative, non-limiting embodiment, a medicalmanifold for delivering one or more fluids to a tissue site includes aplurality of exterior conduits coupled in a spaced relationships todefine an interior space between the plurality of exterior conduits. Theinterior space comprises a central conduit. The medical manifold furtherincludes a plurality of apertures formed on the plurality of externalconduits.

According to another illustrative, non-limiting embodiment, a method ofmanufacturing a medical manifold includes forming four first conduitswith each first conduit touching two other first conduits, forming asecond conduit from the four first conduits, and using a core pin tocreate apertures in the first conduits and the second conduit.

Other features and advantages of the illustrative embodiments willbecome apparent with reference to the drawings and detailed descriptionthat follow.

BRIEF DESCRIPTION OF THE DRAWINGS

To provide a more complete understanding of the illustrative,non-limiting embodiments and certain of its features and advantages,reference is now made to the following description taken in conjunctionwith the accompanying drawings, in which:

FIG. 1 is a schematic diagram of a reduced-pressure treatment system forapplying reduced pressure to a subcutaneous tissue site in accordancewith an illustrative embodiment;

FIG. 2 is schematic, perspective view of a manifold according to anillustrative embodiment;

FIG. 3 is a schematic, longitudinal cross-sectional view of the manifoldof FIG. 2; and

FIG. 4 is a schematic, lateral cross-sectional view of a manifoldaccording to another illustrative embodiment.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

In the following detailed description of the preferred embodiments,reference is made to the accompanying drawings that form a part hereof,and in which is shown by way of illustration specific preferredembodiments in which the invention may be practiced. These embodimentsare described in sufficient detail to enable those skilled in the art topractice the invention, and it is understood that other embodiments maybe utilized and that logical structural, mechanical, electrical, andchemical changes may be made without departing from the spirit or scopeof the invention. To avoid detail not necessary to enable those skilledin the art to practice the invention, the description may omit certaininformation known to those skilled in the art. The following detaileddescription is, therefore, not to be taken in a limiting sense, and thescope of the present invention is defined only by the appended claims.

Referring primarily to FIG. 1, a reduced-pressure treatment system 100,which applies reduced pressure to a tissue site 105, is shown accordingto an illustrative embodiment. In the non-limiting illustrativeembodiment of FIG. 1, the tissue site 105 is a bone tissue site and, inparticular, the tissue site 105 is a fracture on bone 112, which is afemur. It is believed that reduced pressure may provide a number ofbenefits. When used to promote bone tissue growth, reduced-pressuretreatment may increase the rate of healing associated with a fracture, anon-union, a void, or other bone defects. Unless otherwise indicated, asused herein, “or” does not require mutual exclusivity. Reduced-pressuretreatment may also be used to improve recovery from osteomyelitis. Thetreatment may further be used to increase localized bone densities inpatients suffering from osteoporosis. Finally, reduced-pressuretreatment may be used to speed and improve osseointegration oforthopedic implants, such as hip implants, knee implants, and fixationdevices.

The tissue site 105 may also be the bodily tissue of any human, animal,or other organism, including adipose tissue, muscle tissue, dermaltissue, vascular tissue, connective tissue, cartilage, tendons,ligaments, or any other tissue. While the tissue site 105 may include awound, diseased tissue, or defective tissue, the tissue site may also behealthy tissue that is not wounded, diseased, or defective. Theapplication of reduced pressure to the tissue site 105 may be used topromote the drainage of exudate and other liquids from the tissue site105, as well as stimulate the growth of additional tissue. In the casein which the tissue site 105 is a wound site, the growth of granulationtissue and removal of exudates and bacteria promote healing of thewound. The application of reduced pressure to non-wounded ornon-defective tissue, including healthy tissue, may be used to promotethe growth of tissue that may be harvested and transplanted to anothertissue location.

The reduced pressure that is applied to the tissue site 105 is providedby a reduced-pressure source 110. As used herein, “reduced pressure”generally refers to a pressure less than the ambient pressure at atissue site that is being subjected to treatment. In most cases, thisreduced pressure will be less than the atmospheric pressure at which thepatient is located. Alternatively, the reduced pressure may be less thana hydrostatic pressure at the tissue site 105. Unless otherwiseindicated, values of pressure stated herein are gauge pressures.

The reduced pressure delivered may be constant or varied (patterned orrandom) and may be delivered continuously or intermittently. Althoughthe terms “vacuum” and “negative pressure” may be used to describe thepressure applied to the tissue site 105, the actual pressure applied tothe tissue site 105 may be more than the pressure normally associatedwith a complete vacuum. Consistent with the use herein, an increase inreduced pressure or vacuum pressure typically refers to a relativereduction in absolute pressure.

The reduced-pressure source 110 may be any device or system thatgenerates or provides a reduced pressure, including, but not limited to,manually operated or powered pumps. The possible sources of reducedpressure are numerous, and non-limiting examples follow. Thereduced-pressure source 110 may include devices that are manuallyactuated, such as bellows pumps, peristaltic pumps, diaphragm pumps,rotary vane pumps, linear piston pumps, pneumatic pumps, hydraulicpumps, hand pumps, foot pumps, multi-chamber pumps, and manual pumps. Asanother non-limiting example, the reduced-pressure source 110 may bewall suction.

The reduced-pressure source 110 provides reduced pressure to tissue site105 via a manifold 115, which may be percutaneously inserted and placedadjacent, or abutting, the tissue site 105. In one embodiment, themanifold 115 includes first conduits 121. Each of the first conduits 121may have a plurality of or at least one first aperture 131. At least oneof the first conduits 121 may be in fluid communication with thereduced-pressure source 110. In another embodiment, each of the firstconduits 121 is in fluid communication with the reduced-pressure source110. Also, at least one of the first conduits 121 may be operable todeliver reduced pressure to the tissue site 105 via the first apertures131. In another embodiment, each of the first conduits 121 is operableto deliver reduced pressure to the tissue site 105 via the firstapertures 131.

The manifold 115 may also include a second conduit 163 that is formed bya portion of each outer surface of the first conduits 121. The secondconduit 163 may be in fluid communication with the first conduits 121via at least one second aperture (see by analogy 240 in FIG. 2).

The reduced pressure provided by the reduced-pressure source 110 isprovided to the manifold 115 via a reduced-pressure delivery conduit,delivery conduit 135. The delivery conduit 135 may deliver reducedpressure from the reduced-pressure source 110 to at least one of thefirst conduits 121 during treatment. In an alternative embodiment, thedelivery conduit 135 may deliver reduced pressure to the second conduit163.

The delivery conduit 135 may be coupled to the manifold 115. As usedthroughout, the term “coupled” includes coupling via a separate object.For example, the delivery conduit 135 is coupled to the manifold 115 ifboth the delivery conduit 135 and the manifold 115 are coupled to one ormore third objects. The term “coupled” also includes “directly coupled,”in which case the two objects touch each other in some way. The term“coupled” also encompasses two or more components that are continuouswith one another by virtue of each of the components being formed fromthe same piece of material. The term “coupled” includes chemicalcoupling, such as via a chemical bond. The term “coupled” also includesfluidly coupled, in which case a first object that is coupled to asecond object is in fluid communication with that second object. Theterm “coupled” may also include mechanical, thermal, or electricalcoupling. Objects that are “coupled” may also be fixedly or removablycoupled. The delivery conduit 135 is fluidly coupled to the manifold115.

The delivery conduit 135 may be any tube or conduit through which a gas,liquid, gel, or other fluid may flow. The delivery conduit 135 may bemade from any material, may be either flexible or inflexible, and mayhave any cross-sectional shape. The possible embodiments of the deliveryconduit 135 are numerous, and non-limiting examples follow.

The delivery conduit 135 may include one or more paths or lumens throughwhich fluid may flow. For example, the delivery conduit 135 may includetwo or more lumens. In this example, one or more lumens may be used todelivery reduced pressure from the reduced-pressure source 110 to atleast one or all of the first conduits 121. Another lumen may be used todeliver fluids, such as air, liquid, antibacterial agents, antiviralagents, cell-growth promotion agents, irrigation fluids, or otherchemically active agents from a fluid source 111, to the second conduit163 of the manifold 115. These fluids may be used to purge (whichincludes partial purging) the manifold 115, including the purging of anyblockages in the manifold 115.

Numerous other devices may be associated with The reduced-pressuretreatment system 100 and typically with the delivery conduit 135.Non-limiting examples of devices include a reduced-pressure feedbacksystem 155, a volume detection system 157, a fluid collection apparatus140, a flow rate monitoring system 167, a blood detection system 159, aninfection detection system 165, a temperature monitoring system 162,etc.

The reduced-pressure feedback system 155 may be operably associated withthe other components of the reduced-pressure treatment system 100 toprovide information to a user of the reduced-pressure treatment system100 indicating a relative or absolute amount of pressure that is beingdelivered to the tissue site 105 or that is being generated by thereduced-pressure source 110. Examples of feedback systems include,without limitation, pop valves that activate when the reduced pressurerises above a selected value and deflection pop valves.

The volume detection system 157 may be included to detect the amount offluid present in a fluid collection apparatus 140. The blood detectionsystem 159 may be included to detect the presence of blood in exudatedrawn from the tissue site 105. The temperature monitoring system 162may be included to monitor the temperature of the tissue site 105. Theinfection detection system 165 may be included to detect the presence ofinfection at the tissue site 105. The infection detection system 165 mayinclude a foam or other substance that changes color in the presence ofbacteria. The foam or other substance may be operably associated withthe delivery conduit 135 such that the color changing material isexposed to exudate from the tissue site 105. The flow rate monitoringsystem 167 may be included to monitor the flow rate of fluids drawn fromthe tissue site 105.

In addition to the above-mentioned components and systems, thereduced-pressure treatment system 100 may include valves, regulators,switches, and other electrical, mechanical, and fluid components tofacilitate administration of reduced-pressure treatment to the tissuesite 105. Other systems or devices may also be associated with thedelivery conduit 135.

Referring now primarily to FIGS. 2 and 3, a manifold 215 is shownaccording to an illustrative embodiment. The manifold 215 is anon-limiting example of the manifold 115 in FIG. 1. FIG. 3 is alongitudinal cross-sectional view of the manifold 215. The manifold 215is adapted to be inserted into a patient and placed at the subcutaneoustissue site, e.g., tissue site 105 in FIG. 1. The manifold 215 includesa plurality of first conduits 221 that are adjacent to one another toform an interior space that defines a second conduit 263 between thefirst conduits 221. The plurality of first conduits 221 may be spaced ina uniform pattern or an irregular pattern and the members of the firstplurality of conduits 221 may be uniform in size or vary. The firstconduits 215 may be coupled one to another by a plurality of bonds,e.g., welds, cement, bonds, etc. The manifold 215 provides areduced-pressure supply function and purging function using the firstconduits 221 and second conduit 263. In one non-limiting example, thesecond conduit 263 may communicate with each of the first conduits 221via a plurality of second apertures 240.

The manifold 215 includes first conduits 221. Each of the first conduits221 has at least one first aperture 231 and at least one second aperture240 formed in a wall 225, e.g., an annular wall. In the non-limitingexamples of FIGS. 2 and 3, each of the first conduits 221 has aplurality of first apertures 231 and a plurality of second apertures 240formed in the wall 225. The first apertures 231 may be uniformly ornon-uniformly spaced from one another and may be uniform or non-uniformin diameter. Also, the second apertures 240 may be uniformly ornon-uniformly spaced from one another and may be uniform or non-uniformin diameter.

In one illustrative embodiment, at least one of the first conduits 221is in fluid communication with a reduced-pressure source, such as thereduced-pressure source 110 in FIG. 1. At least one of the firstconduits 221 may deliver reduced pressure from the reduced-pressuresource to a tissue site via the first apertures 231. The first conduits221 may also deliver reduced pressure to any portion of the manifold215, such as a distal end 282 of the manifold 215. In anotherillustrative embodiment, each of the first conduits 221 is in fluidcommunication with a reduced-pressure source, and each of first conduits221 delivers reduced pressure to a subcutaneous tissue site via thefirst apertures 231. The flow of fluid in a direction away from thedistal end 282 of the manifold 215 through the first conduits 221 isrepresented by the arrows 271. The flow of fluid away from the manifold215 in this manner causes a reduced pressure at the first conduits 221or at least a portion of the first conduits to be transferred to atissue site via the first apertures 231.

Each the first apertures 231 allow fluid communication between the firstconduits 221 and a space outside of the manifold 215, such as a tissuesite. In addition to permitting the transfer of reduced pressure fromthe first conduits 221 to a tissue site, the first apertures 231 mayalso allow exudate or other fluid from the tissue site to enter thefirst conduits 221. The flow of fluid from the space outside of themanifold 215 into the first conduits 221 is represented by arrows 272.

The first conduits 221 are shown with a circular cross-sectional shape.However, the first conduits 221 may have any cross-sectional shape,including an elliptical, diamond, triangular, square, polygonal, etc.

In addition, although FIG. 2 shows the manifold 215 having four firstconduits 221, the manifold 215 may have any number of first conduits.For example, the manifold 215 may have two or more first conduits 221that at least partially encompass and form the second conduit 263. Thesecond conduit 263 may be centrally disposed between the two or morefirst conduits 221 and typically between at least three of the firstconduits 221.

Each of the first apertures 231 is shown to have a circularcross-sectional shape. However, each of the first apertures 231 may haveany cross-sectional shape, such as an elliptical or polygonalcross-sectional shape. In another example, each of the first apertures231 may be slits that extend along all or a portion of the firstconduits 221. As used herein, a “slit” is any elongated hole, aperture,or channel. In one illustrative embodiment, each of the slits may besubstantially parallel to one another.

The second conduit 263 of the manifold 215 is formed by a portion ofeach of the outer surfaces 284 and 286 of the first conduits 221. Eachof the second apertures 240 is located on the portion of each of theouter surfaces 284 and 286 of the first conduits 221 that form thesecond conduit 263. The second conduit 263 is typically centrallyformed, or otherwise disposed, between the first conduits 221. Thesecond conduit 263, which is another non-limiting embodiment of thesecond conduit 163 in FIG. 1, is in fluid communication with the firstconduits 221 via the second apertures 240.

The second conduit 263 may be in fluid communication with a fluidsource, such as the fluid source 111, in FIG. 1 that supplies a fluid tothe tissue site or portions of the first conduit 221. The second conduit263 may receive fluid from the fluid source. In one embodiment, thesecond conduit 263 delivers the fluid to each of the first conduits 221via the second apertures 240. The second conduit 263 may also deliver afluid to a distal portion of the manifold 215, including the end of themanifold 215. The second conduit 263 may also deliver a fluid to thetissue space around the manifold 215. The fluid delivered by the secondconduit 263 may be a gas, such as air, or a liquid. The flow of fluiddelivered by the second conduit 263 is represented by arrows 273. In analternative embodiment, fluid from a fluid source may be deliveredtoward the distal end 282 of the manifold 215 by any one or more of thefirst conduits 221.

In one non-limiting embodiment, the first conduits 221 draw fluid fromthe second conduit 263 via the second apertures 240. In this embodiment,reduced pressure from a reduced-pressure source causes the fluid to bedrawn from the second conduit 263 to the first conduits 221 via thesecond apertures 240. In another non-limiting embodiment, positivepressure provided by the fluid source and delivered by the secondconduit 263 forces, or otherwise causes, the fluid to be transferredfrom the second conduit 263 to the first conduits 221 via the secondapertures 240. The transfer of fluid from the second conduit 263 to thefirst conduits 221 via the second apertures 240 facilitates the purgingfunction of the manifold 215 that helps to remove or reduce anyblockages that form in the manifold 215. The first conduits 221 mayinclude any number of second apertures 240, which number may control therate of fluid being transferred from the second conduit 263 to the firstconduits 221.

In one embodiment, the manifold 215 may also include an end cap 270 thatis adapted to be coupled or is coupled to the distal end 282 of themanifold 215 to form a distribution space. Fluid delivered by the secondconduit 263 may be transferred from the second conduit 263 to the firstconduits 221 via the space that is formed by coupling the end cap 270 tothe distal end 282 of the manifold 215. In one embodiment, the space mayprovide the sole passageway through which fluid is transferred from thesecond conduit 263 to the first conduits 221. In this embodiment, nosecond apertures 240 may be present on the first conduits 221 or aminimal number of apertures 240.

In one illustrative embodiment, the second apertures 240 are absent ornot open to the outside of the manifold 215 and fluid, such as liquid orair, may be drawn into the second conduit 263 by opening a valve toatmosphere (e.g., air purge). The valve is in fluid communication withthe second conduit 263. Thus, fluid may be drawn through the secondconduit 263 and back toward a reduced-pressure device via the firstconduits 221, which, while under reduced pressure, may supply the forceto draw any clot/clog formations, such as fibrin formations, out of themanifold 215 and toward the reduced-pressure source. In this embodiment,no supply port for the second conduit 263 may be present on the outersurface of the manifold 215. In this illustrative embodiment, the secondconduit 263 may be completely enclosed by the first conduits 221,including a distal end of the second conduit 263, and thus may be closedfrom an outside environment, such as a tissue space. The second conduit263 communicates proximate end cap 270 from the second conduit 263 tothe first conduits 221. This illustrative embodiment may allow for afluid to be contained within the manifold 215 as the fluid moves fromthe second conduit 263 to the first conduits 221. Thus, in thisembodiment, the likelihood of the fluid moving out into the tissue spaceis reduced or eliminated.

In one illustrative, non-limiting embodiment, the manifold 215 is formedwith four of the first conduits 221. As before, the first conduits 221form the second conduit 263. Each of the four first conduits 221 touchat least two other of the four first conduits 221. In this embodiment,the four first conduits 221 and second conduit 263 are formed byco-extruding the conduits 221, 263. After the extruding the conduits221, 263, a core pin may be used to pierce the conduits straight throughto form the first apertures 231. Thus, for example, a core pin maypierce the upper right (for the orientation in FIG. 2) first conduit 221and the lower left first conduit 221—and concomitantly pierce the secondconduit 263. This may be repeated as many times as desired and atvarious orientations.

In the example in which the fluid in second conduit 263 is a liquid, theliquid may be pumped in or gravity fed down the second conduit 263 suchthat the only pathway for the liquid is through the second apertures 240and into the first conduits 221, along the first conduits 221, andtoward the reduced-pressure source. The manifold 215 preferably has asymmetrical design, and the symmetrical design of the manifold 215allows the manifold 215 to be used in any spatial orientation to achievethe same or similar results in each position.

In another illustrative embodiment, a supplied fluid may be allowed toenter the space surrounding the manifold 215, such as a tissue space.For example, the fluid may exit the manifold 215 at the opening at thedistal end 282 of the second conduit 263. The fluid may then be drawninto the first conduits 221.

In one illustrative embodiment, a method for applying reduced pressureto a subcutaneous tissue site includes applying the manifold 215 to thesubcutaneous tissue site. The manifold 215 may be percutaneouslyinserted into a patient, and the manifold 215 may be positioned adjacentto or abutting the subcutaneous tissue site. The symmetrical design ofthe manifold 215 may facilitate the implantation of the manifold in anyorientation.

In one illustrative embodiment, a method of manufacturing an apparatusfor applying reduced pressure to a subcutaneous tissue site includesproviding first conduits 221. The method may also include coupling thefirst conduits 221 to one another to form the second conduit 263. Thesecond conduit 263 is formed by a portion of each outer surface 284 and286 of the first conduits 221. The method may also include providing adelivery conduit for delivering reduced pressure to at least one of thefirst conduits 221. The method may also include fluidly coupling thedelivery conduit to the first conduits 221 and the second conduit 263.

Referring now primarily to FIG. 4, another illustrative, non-limitingembodiment of a manifold 315 is presented. The manifold 315 includes aplurality of first conduits 321 that are coupled in a spacedrelationship with a plurality of bonds 317. Each of the plurality offirst conduits 321 may have differing diameters or the same diameters,and in this illustrative embodiment, one conduit 323 of the firstconduits conduit 321 is shown with a smaller diameter than the others.It should be understood in this and the other illustrative embodimentsthat the diameter of the first conduits may be varied or may be uniform.

The manifold 315 includes a second conduit 363 formed by a portion ofeach of the outer surfaces 384 of the first conduits 221. The secondconduit 363 is shown with broken lines and in this illustration is astar-like shape. One or more additional conduits, such as third conduit365, may be disposed within the second conduit 363. The additionalconduit 365 may be sized to touch each of the plurality of firstconduits 321 as shown or may be smaller in size. The additional conduit,or third conduit 365, may be coupled to one or more of the firstconduits 221. In an alternative embodiment (not shown), the firstconduits 321 may not form or fully form the second conduit, but themanifold 315 may have the additional conduit 365 at a center positionadjacent to each of the first conduits 321.

The additional conduit 365 may carry a purging fluid or may be used tocarry other fluids to or from a distal end (not shown) of the manifold315. The space 367 formed exterior to the additional conduit 365 and onthe interior of the second conduit 363 may carry a purging fluid to beintroduced through apertures in the outer wall portion 384 of the firstconduits 321, and the additional conduit 365 may carry a purging fluidto an end cap (e.g. end cap 270 in FIG. 3) to introduce a purging fluidinto the first conduits 321 at the distal end. The end cap 270 may beattached to the distal end 282 using interference fit, RF welding, RFformed tip process, solvent bonding, or any other coupling technique.

Although the present invention and its advantages have been disclosed inthe context of certain illustrative, non-limiting embodiments, it shouldbe understood that various changes, substitutions, permutations, andalterations can be made without departing from the scope of theinvention as defined by the appended claims. It will be appreciated thatany feature that is described in a connection to any one embodiment mayalso be applicable to any other embodiment.

We claim:
 1. A manifold for applying reduced pressure to a subcutaneoustissue site, the manifold comprising: a plurality of first conduits,each of the plurality of first conduits having a wall with at least onefirst aperture and at least one second aperture, at least one of theplurality of first conduits operable to deliver reduced pressure to thesubcutaneous tissue site via the at least one first aperture; whereinthe plurality of first conduits are coupled in a spaced arrangement thatforms an interior space; a second conduit comprising the interior spaceand formed by a portion of each wall of the plurality of first conduits,the second conduit being in fluid communication with the plurality offirst conduits via the at least one second aperture.
 2. The manifold ofclaim 1, wherein each of the plurality of first conduits includes aplurality of first apertures.
 3. The manifold of claim 1, furthercomprising: wherein each of the plurality of first conduits includes aplurality of second apertures; and wherein the plurality of secondapertures are uniformly spaced from one another.
 4. The manifold ofclaim 1, further comprising an end cap adapted to be coupled to a distalend of the manifold to form a distribution space.
 5. The manifold ofclaim 1, wherein each of the plurality of first conduits has a circularcross-sectional shape.
 6. The manifold of claim 1, wherein across-sectional shape of each of the plurality of first conduits is oneof an ellipse, a diamond, a triangle, a square, or a polygon.